With 49 MHz technology, lightweight portability and sound lights that let you see baby's activity level, The First Years 49 MHz Two Receiver Monitor enables you to enjoy peace of mind when you're away from your baby. For added convenience, it includes two receivers so you can keep each receiver in a different room or so two listeners can have a monitor handy at all times. Plus, low battery indicator provides extra reassurance that when your monitor is quiet, it just means that baby is sleeping-not that your monitor isn't working.